Survival of Australian Anchovy (Engraulis australis) Eggs and Larvae in a Heat Trap

1974 ◽  
pp. 373-381 ◽  
Author(s):  
P. M. Powles
Keyword(s):  
Author(s):  
Tatiana Vasilievna Pomogaeva ◽  
Aliya Ahmetovna Aseinova ◽  
Yuriy Aleksandrovich Paritskiy ◽  
Vjacheslav Petrovich Razinkov

The article presents annual statistical data of the Caspian Research Institute of Fishery. There has been kept track of the long term dynamics of the stocks of three species of Caspian sprat (anchovy, big-eyed kilka, sprat) and investigated a process of substituting a food item of sprats Eurytemora grimmi to a small-celled copepod species Acartia tonsa Dana. According to the research results, there has been determined growth potential of stocks of each species. Ctenophoran-Mnemiopsis has an adverse effect on sprat population by eating fish eggs and larvae. Ctenophoram - Mnemiopsis is a nutritional competitor to the full-grown fishes. The article gives recommendations on reclamation of stocks of the most perspective species - common sprat, whose biological characteristics helped not to suffer during Ctenophoram outburst and to increase its population during change of the main food item. Hydroacoustic survey data prove the intensive growth of common sprat biomass in the north-west part of the Middle Caspian. According to the results of the research it may be concluded that to realize the volumes of recommended sprat catch it is necessary to organize the marine fishery of common sprat at the Russian Middle Caspian shelf.


Author(s):  
Peter Munk ◽  
Jørgen G. Nielsen

This chapter describes the taxonomy of fish eggs and larvae. Most fish eggs and larvae are planktonic, and are commonly found in plankton net tows. Collectively these fish stages are referred to as ichthyoplankton. The chapter covers their life cycle, ecology, and general morphology. It includes a section that indicates the systematic placement of the taxon described within the tree of life, and lists the key marine representative illustrated in the chapter (usually to genus or family level). This section also provides information on the taxonomic authorities responsible for the classification adopted, recent changes which might have occurred, and lists relevant taxonomic sources.


2019 ◽  
Vol 128 (1) ◽  
pp. 107-121 ◽  
Author(s):  
Katherine E Dale ◽  
M Timothy Tinker ◽  
Rita S Mehta

Abstract The geographical range of many marine species is strongly influenced by the dispersal potential of propagules such as eggs and larvae. Here, we investigate morphological diversity and the effect of body shape on geographical range of leptocephali, the unique, laterally compressed larvae of eels (order Anguilliformes). We used phylogenetically informed analyses to examine the morphological variation of larvae for 17 Eastern Pacific eel species from three adult habitats. We also investigated whether morphological traits of leptocephali could predict larval latitudinal range, hypothesizing that body shape may influence passive dispersal via currents. We found that no two species shared the same multivariate growth trajectories, with the size and scaling of pectoral fin length and snout-to-anus length being particularly variable. Larvae with longer relative predorsal and snout-to-anus lengths at median sizes exhibited wider larval geographical ranges. Body aspect ratio and maximum body length at metamorphosis, two traits we hypothesized to be important for passive transport, were not significant predictors of maximal larval range. We discovered an increase in phylogenetic signal over larval development as eels approach metamorphosis, potentially due to similar selective pressures between related species (such as juvenile habitat or adult morphology). Lastly, we conclude that larval body shape is probably influenced by adult habitat and adult morphology.


1899 ◽  
Vol 31 (4) ◽  
pp. 73-76
Author(s):  
F. M. Webster

With the constantly increasing activity in applied entomology in America, the necessity for rooms or apartments especially adapted for the study of the development of insects is becoming each year more imperative. The insectary has, in fact, become almost as necessary to the working entomologist as has the laboratory to the chemist. While it is especially true in entomological investigations that one must “study nature where nature is,” it is equally true that on cannot, in all cases, watch with the necessary care and constant application in the fields that he will be able to do in a faily well equipped insectary. Not only can forms be transported thousands of miles while in an inactive state and their development watched at close range, as it were, but eggs and larvae may be brought in during late autumn or winter and studied through their various stages, frequently long before they have appeared outside; and in cases of uncommon or unfamiliar forms this will give the investigator a vast amount of information that he can use to great advantage when the species appears in the fields under a natural condition, perhaps months later.


2010 ◽  
Vol 27 (5) ◽  
pp. 402-409 ◽  
Author(s):  
Wei Jiang ◽  
Huan-Zhang Liu ◽  
Zhong-Hua Duan ◽  
Wen-Xuan Cao

Parasitology ◽  
1972 ◽  
Vol 64 (3) ◽  
pp. 451-460 ◽  
Author(s):  
T. E. Gibson ◽  
G. Everett

The development and survival of the eggs and larvae of O. circumcincta was studied by spreading the daily faecal output of a sheep over a 2 m square grass plot for 1 week. Observations were carried out for 3 years on material spread at 4-weekly intervals and broadly similar results were obtained in each year. Development time was long in eggs placed outside in January, February, March, November and December. Yields of larvae were small and all were dead within 5 months. During the rest of the year development time was about 2 weeks, yields of larvae were high and larvae survived until July or August of the following year. The significance of these findings in devising systems of grazing management to control parasitic gastroenteritis is discussed.


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